package com.briup.MR.InOutFormat;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.NLineInputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

/**
 * yarn jar HdfsClientDemo-1.0-SNAPSHOT.jar com.briup.MR.InOutFormat.NLineMR -D input=/user/hdfs/regex/regex.txt -D output=/user/hdfs/regex/Nline_result
 */
public class NLineMR extends Configured implements Tool {
    public int run(String[] strings) throws Exception {
        Configuration conf = getConf();
        String input = conf.get("input");
        String output = conf.get("output");

        Job job = Job.getInstance(conf);
        job.setJarByClass(this.getClass());
        job.setJobName("NLineMR");
        //按照行化数据片
        //读取每一行数据，键为每一行的偏移位置，值为整行内容
        NLineInputFormat.setNumLinesPerSplit(job,2);
        job.setInputFormatClass(NLineInputFormat.class);
        NLineInputFormat.addInputPath(job,new Path(input));
        TextOutputFormat.setOutputPath(job,new Path(output));
        return job.waitForCompletion(true)?0:-1;
    }

    public static void main(String[] args) throws Exception {
        System.exit(new ToolRunner().run(new NLineMR(),args));
    }
}
